1. Field of the Invention
The present invention relates to devices, kits and methods for the detection of hookworm in animals. More particularly, the invention relates to antibody-based devices, kits and methods for capturing and detecting hookworm antigens in an animal's feces for the purpose of diagnosing that animal as having or not having a hookworm infection. Even more particularly, the invention relates to antibody-based devices, kits and methods for diagnosing a hookworm infection in an animal before or after hookworm ova first appear in the animal's feces. Still more particularly, the invention relates to antibody-based devices, kits and methods for confirming the presence or absence of a hookworm infection in an animal regardless of whether that animal is infected with one or more of roundworm, whipworm, tapeworm and heartworm.
2. Description of the Prior Art
Hookworms are bloodsucking intestinal parasites that can cause their host to suffer serious illness, such as anemia, wasting and retarded development. For example, the hookworm Ancylostoma caninum causes significant disease in both dogs and humans (Prociv et al., Acta Trop. 1996 September; 62(1):23-44). Diagnosis of a hookworm infection typically is performed by following the fecal flotation method, which involves obtaining a fecal sample from the animal being diagnosed and visually inspecting it by microscope for hookworm ova. This microscopic diagnosis method, however, is time consuming and requires specialized equipment. Further, the accuracy of diagnosis using this method is highly dependent upon the skill and expertise of the clinician performing the inspection. (For example, a novice eye often will mistake ova of other parasitic nematodes for those of hookworm and vice versa.) This potential for misdiagnosis is unfortunate because a misdiagnosed animal may be given a treatment that is ineffective against hookworm, and therefore one that would not alleviate the animal's suffering or stop the progressive wasting of its health.
Another significant limitation of diagnosis by microscopic detection of ova is that because hookworm eggs generally are not detectable in host feces until well after infection manifests, it does not allow for early detection of hookworm infection. For example, hookworm ova generally do not appear in canine feces until about 17 days after oral ingestion of the parasite by the canine. This is a problem because symptoms such as severe weight loss and bloody diarrhea often distress the host before hookworm ova first appear in the feces. Early detection therefore is highly desirable.
For these reasons, there remains great potential for the development of a device, kit and method which can be used to correctly diagnose an animal as having or not having a hookworm infection, specifically, as opposed to a nematode infection, generally. There also remains great potential for such a device and method that can be used to make this diagnosis soon after the animal becomes infected. Further, it is desirable to have such a device and method suitable to detect hookworm in an animal sample that is easily obtainable. A particularly convenient sample is feces because unlike blood, for example, feces are readily excreted by animals. The ability to use an animal sample that is easily obtained would obviate the need to transport the animal, which in some cases may be too sick to travel, to a veterinary professional for sample collection, such as may be needed when blood, for example, must be collected.
Given that the needed device, kit and method should be able to detect the presence or confirm the absence of hookworm in an animal whether or not hookworm organisms, including hookworm ova, are in the test sample taken from the animal, the device and method should be aimed at the molecular level. In particular, the device, kit and method may be an antibody-based device and method which are capable of detecting the presence or absence of hookworm-specific antigens. While antibody-based strategies for detecting nematode antigens generally exist, none specifically have allowed the early detection of, or confirmation of the absence of, hookworm in a fecal sample from an animal that may also be infected by one or more of roundworm, whipworm, tapeworm and heartworm.
What is needed therefore is a device, kit and method for testing a fecal sample from an animal to determine whether the animal is infected with hookworm. The needed device, kit and method further should be able to specifically detect the presence or absence of hookworm in an animal whether or not hookworm ova are present in the animal's feces. Even further, the needed device, kit and method should be able to specifically detect hookworm in a fecal sample that may also include one or more of roundworm, whipworm, tapeworm and heartworm.